Antenna system for signal-attenuating containers

ABSTRACT

A system can include a container that includes a cabinet capable of attenuating or blocking wireless signals, an AED located within the cabinet, an internal patch antenna removably mounted to an internal surface of the cabinet, an external patch antenna removably mounted to an external surface of the cabinet, and an electrical connection between the internal patch antenna and the external patch antenna. The internal and external patch antennas can be configured to transmit wireless signals at a particular frequency and to receive wireless signals at the particular frequency. The system can be configured such that the internal patch antenna is operative to receive a first wireless signal from the AED, a first electrical signal based on the first wireless signal is provided via the electrical connection to the external patch antenna, and a second wireless signal based on the first electrical signal is radiated by the external patch antenna.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/864,444 filed Nov. 26, 2013 entitled “ANTENNA SYSTEM FORSIGNAL-ATTENUATING CONTAINERS,” which is a divisional of U.S. patentapplication Ser. No. 14/090,824 filed Nov. 26, 2013, entitled “ANTENNASYSTEM FOR SIGNAL-ATTENUATING CONTAINERS,” (now U.S. Pat. No. 9,172,129issued Oct. 27, 2015), the contents of each are hereby incorporated byreference in its entirety.

BACKGROUND

An automated external defibrillator (AED) is a portable electronicdevice that treats cardiac arrhythmias through defibrillation. Suchcardiac arrhythmias are potentially life-threatening and the sooner thatan AED can be used to treat a patient, the greater the likelihood thatthe defibrillation by the AED will benefit the patient. Defibrillationby an AED can include the application of electrical therapy which stopsthe arrhythmia and allows the heart to reestablish an effective rhythm.Some AEDs can automatically diagnose arrhythmias and tailor patienttreatment to meet the diagnosis. AEDs are typically designed so thatsomeone without extensive medical training can effectively use AEDs toprovide defibrillation treatment, though many AED training programs areavailable for basic training on how to use an AED.

Because patients typically benefit from administering AED treatmentsooner, many public places, such as libraries, movie theaters, hotels,high-rise buildings, and the like, are placing AEDs in accessiblelocations. While public places may want to make AEDs accessible, theyalso want to ensure that AEDs are protected from inadvertent,unintended, or nefarious use, such as use by a child, by a vandal, andthe like. To protect AEDs while making them available for use, AEDs arefrequently placed inside of protective containers, such as metalcabinets or containers. Other devices, such as fire extinguishers, aresimilarly placed in protective containers to prevent unwanted uses ofthe devices while making the devices readily available for use.

SUMMARY

Illustrative embodiments of the present invention include, withoutlimitation, methods, structures, and systems. In one embodiment, asystem can include a container that includes a metal cabinet, an AEDlocated within the metal cabinet, an internal patch antenna removablymounted to an internal surface of the metal cabinet, an external patchantenna removably mounted to an external surface of the metal cabinet,and an electrical connection between the internal patch antenna and theexternal patch antenna. The AED can be configured to communicate, viawireless signals at one or more particular frequencies, with otherdevices or networks. Such communication to and from the AED can used fora number of purposes, such as AED software updates, query of AED stateor errors, AED event data transmission, or remaining shelf life of timesensitive components of the AED. The internal patch antenna can beconfigured to transmit wireless signals at the one or more particularfrequencies and to receive wireless signals at the one or moreparticular frequencies. The external patch antenna can be configured totransmit wireless signals at the one or more particular frequencies andto receive wireless signals at the one or more particular frequencies.The system can be configured such that the internal patch antenna isoperative to receive a first wireless signal from the AED, a firstelectrical signal based on the first wireless signal is provided via theelectrical connection to the external patch antenna, and a secondwireless signal based on the first electrical signal is radiated by theexternal patch antenna.

In one example, the system can be further configured such that theexternal patch antenna is operative to receive a third wireless signal,a second electrical signal based on the third wireless signal isprovided via the electrical connection to the internal patch antenna,and a fourth wireless signal based on the second electrical signal isradiated from the internal patch antenna. In other examples, the metalcabinet can include a door and a doorway. The electrical connection canbe routed through the doorway. The electrical connection can include aribbon cable. The electrical connection can be routed through a hingearea of the doorway. The electrical connection can be routed through ahole in the metal cabinet.

In another embodiment, a system can include a container, a devicelocated within the container, an internal patch antenna removablymounted to an internal surface of the container, an external patchantenna removably mounted to an external surface of the container, andan electrical connection between the internal patch antenna and coupledto the external patch antenna. The device can be configured tocommunicate wireless signals at one or more particular frequencies. Theinternal patch antenna can be configured to transmit wireless signals atthe one or more particular frequencies and to receive wireless signalsat the one or more particular frequencies. The external patch antennacan be configured to transmit wireless signals at the one or moreparticular frequencies and to receive wireless signals at the one ormore particular frequencies. The system can be configured such that theinternal patch antenna is operative to receive a first wireless signalfrom the device, a first electrical signal based on the first wirelesssignal is provided via the electrical connection to the external patchantenna, and a second wireless signal based on the first electricalsignal is radiated by the external patch antenna.

In one example, the system can be further configured such that theexternal patch antenna is operative to receive a third wireless signal,a second electrical signal based on the third wireless signal isprovided via the electrical connection to the internal patch antenna,and a fourth wireless signal based on the second electrical signal isradiated from the internal patch antenna. In other examples, the one ormore frequencies can include at least one of a cellular networkfrequency, a Wi-Fi frequency, or an RFID tag frequency. The one or morefrequencies can include a plurality of frequencies. The device can beconfigured to communicate wireless signals at the one or more particularfrequencies by transmitting an RFID signal from an RFID tag. Thecontainer can include at least one of a cabinet, a storage room, avehicle trunk, a vehicle compartment, an elevator, a subway compartment,a train compartment, an aircraft compartment, or a vehicle.

In another embodiment, an apparatus can include a first patch antenna, asecond patch antenna, and an electrical connection between the firstpatch antenna and the second patch antenna. The first patch antenna canbe configured to transmit wireless signals at one or more particularfrequencies and to receive wireless signals at the one or moreparticular frequencies. The second patch antenna can be configured totransmit wireless signals at the one or more particular frequencies andto receive wireless signals at the one or more particular frequencies.Each of the first patch antenna and the second patch antenna can includea ground plane, a spacer disposed on the ground plane where the spacerincludes a magnetic material, and a patch disposed on the spacer.

The present invention is not limited to any specific design orconfiguration of patch antennae. In view of the present disclosure,those of skill in the art will appreciate that a patch antenna is a typeof radio antenna with a low profile suited for mounting on a flatsurface. A patch antenna typically includes a flat rectangular sheet ofmetal mounted over a larger sheet of metal called a ground plane. Theassembly can be contained inside a plastic radome, which protects theantenna structure from damage. Patch antennas are suited to be used inthe illustrative embodiments of the present invention since they areeasy to fabricate and modify for a particular application. The two metalsheets together form a resonant microstrip transmission line with alength of approximately one-half wavelength. A patch antenna is usuallyconstructed on a dielectric substrate, using the same materials andlithography processes used to make printed circuit boards.

BRIEF DESCRIPTION OF THE DRAWINGS

Throughout the drawings, reference numbers may be re-used to indicatecorrespondence between referenced elements. The drawings are provided toillustrate example embodiments described herein and are not intended tolimit the scope of the disclosure.

FIG. 1 depicts an example of a device that is stored in a container.

FIGS. 2A to 2D depict a system that increases the ability of a device ina container to communicate wirelessly with a device or network outsideof the container.

FIGS. 3A to 3C depict views of an example patch antenna.

FIGS. 4A to 4D depict various embodiments of patch antennas.

FIGS. 5A to 5C depict examples of cross sections of patch antennas thatinclude protective coverings.

FIG. 6 depicts a cross-sectional view of an example of a container inwhich a device is stored.

FIGS. 7A and 7B depict various testing arrangements for testing a patchantenna system.

FIGS. 7C to 7E depict possible orientations of the container withrespect a wireless transmitter.

FIG. 8 depicts another type of container that could benefit from the useof a patch antenna system.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

FIG. 1 depicts an example of a device 110 that is stored in a container120. The container 120 can be a cabinet, such as a metal cabinet, asdepicted in FIG. 1. The container 120 can take a number of other forms,such as a storage room, a vehicle trunk, a vehicle compartment, anelevator, a subway compartment, a train compartment, an aircraftcompartment, a vehicle, and the like. The container 120 can include adoor 121. The door 121 depicted in FIG. 1 is a hinged door, though manyother types of doors could be used. The door 121 can be a solidmaterial, such as metal, or a combination of materials, such as a metalframe with a plastic or glass window.

Devices stored in containers increasingly have a need to communicatewirelessly with communication devices that are outside of thecontainers. For example, some AEDs may be able to communicate via aWiFi, cellular, RFID, or other wireless network to provide notificationsdevice location, software updates or query of device state or errors(collectively referred to as “readiness data”), information about deviceevent data, information about remaining shelf life of time sensitivedevice components, or any other type of information. In another example,some fire extinguisher devices may be able to communicate via a wirelessnetwork to provide information similar to those types of informationdescribed above with respect to the AED above.

In another example, a device inside of a container may have a radiofrequency indentation (RFID) tag that can be used for asset tracking. Inthis scenario, the RFID tag on the device may transmit a radio signalthat can identify the tag and a tracking device may receive the signaland identify that the particular device is within range of the trackingdevice. For example, a tracking device may be placed inside of a room ata hospital and read all RFID signals from RFID tags that are associatedwith equipment in the room. The tracking device may record all thedevices determined to be in the room, and those devices can be trackedwithout a user needing to visually identify each of the devices.Avoiding the need to visually identify each device can be helpful,especially when one or more devices are stored in one or morecontainers.

One difficulty with devices stored in containers communicatingwirelessly is that the containers may block wireless signals orattenuate signal strength of wireless signals. By attenuating orblocking wireless signals, containers can make wireless communicationbetween a device inside of the container with a device or networkoutside of the container difficult or impossible.

FIGS. 2A-2D depict a system that increases the ability of a device 210in a container 220 to communicate wirelessly with a device or networkoutside of the container. The system also includes an antenna system 230that includes an internal patch antenna 231 and an external patchantenna 232. Each of the internal patch antenna 231 and the externalpatch antenna 232 can be tuned to one or more target frequencies. Apatch antenna is tuned to a target frequency when it is capable ofsending and receiving wireless signals at or near that target frequency.Particular frequencies that may be target frequencies includefrequencies that are used by cellular networks, such as 850 MHz, 900MHz, 1,800 MHz, or 1,900 MHz, frequencies that are used by Wi-Finetworks, such as 2.4 GHz, and frequencies used by FRID tags, such as120-150 kHz, 13.56 MHz, 433 MHz, 865-868 MHz, 902-928 MHz, 2450-5800MHz, or 3.1-10 GHz. In one embodiment, each of the internal patchantenna 231 and the external patch antenna 232 can be tuned to one ormore of a cellular network frequency, a Wi-Fi frequency, or an RFID tagfrequency. In some embodiments, a device with wireless communicationcapability can be provided with the antenna system 230 so that a user orinstaller can upgrade or retrofit a previously installed container toenhance the ability of the device to wirelessly communicate with devicesor networks outside of the container. For example, when replacing anolder AED that does not communicate wirelessly with a new AED that doescommunicate wirelessly, the new AED may be placed in the same cabinet asthe old AED. However, since the old AED did not have the ability tocommunicate wirelessly, a patch antenna system could be installed on thecabinet at the time that the new AED is installed. In this case, it maybe helpful for the patch antenna system to be provided as a kit with thenew AED.

The internal patch antenna 231 and the external patch antenna 232 can beremovably mounted to one of the sides of the container 220. A patchantenna is removably mounted to the container if it is mounted to thecontainer in a way that is easily removed, such as using a magneticmounting, an adhesive mounting that permits the patch antenna to bepeeled off of the container by hand, a hook and loop mounting, orsimilar mounting. A patch antenna is not removably mounted to thecontainer if it is mounted to the container using screws, rivets, bolts,or other similar fasteners, or if the patch antenna is permanentlyaffixed to the container, such as if it is welded to the container.

The internal patch antenna 231 and the external patch antenna 232 areconnected via an electrical connection 233. The electrical connectioncan be a low profile ribbon cable, a flexible trace, a coaxial cable, orany other type of electrical connection that can carry signals betweenthe internal patch antenna 231 and the external patch antenna 232. Suchalternative types of electrical connections may also include those whichare non-contact in nature. An example of non-contact electricalconnection between antennas could include inductive and capacitivecoupling, where the electrical signals are passed across/through thewall of the container. Conductors are referred to as mutual-inductivelycoupled or magnetically coupled when they are configured such thatchange in current flow through one wire induces a voltage across theends of the other wire through electromagnetic induction. In such anembodiment, the wall of the container residing between the internal andexternal antennas, regardless of metal composition type, can be factoredas a component in the proper tuning and matching of the non-contactelectrical connection.

FIG. 2B depicts the passing of signals inside of the container 220,outside of the container 220, and between the inside and the outside ofthe container 220. The internal patch antenna 231 can receive a firstwireless signal 241, the internal patch antenna 231 can send a firstelectrical signal 242 to the external patch antenna 232 via theelectrical connection 233, and the external patch antenna 232 cantransmit a second wireless signal 243 outside of the container 220. Thesecond wireless signal 243 can be a continuation of the first wirelesssignal 241, though some losses could be incurred in the antenna system230. The information carried by the first wireless signal 241 is alsocarried in the second wireless signal 243. Similarly, the external patchantenna 232 can receive a third wireless signal 244 from outside thecontainer 220, the external patch antenna 232 can send a secondelectrical signal 245 to the internal patch antenna 231 via theelectrical connection 233, and the internal patch antenna 231 cantransmit a fourth wireless signal 246 inside of the container 220. Thefourth wireless signal 246 can be a continuation of the third wirelesssignal 244, though some losses could be incurred by the antenna system230.

The size and shape of the electrical connection 233 can be selectedbased on how the electrical connection 233 is fed between the internalpatch antenna 231 and the external patch antenna 232. FIG. 2C depicts across-sectional view of the embodiment shown in FIG. 2A looking downfrom the top of the container 220. In the embodiment depicted in FIGS.2A and 2C, the electrical connection 233 is fed through the opening inthe container 220 that can be covered by the door 221. In this case, athin ribbon cable can be used as the electrical connection 233 withouthaving a significantly adverse effect on the closing of the door 221.While a ribbon cable may not permit the door 221 to fully close, theribbon cable may still allow the door 221 to latch. In this way, theantenna system 230 can be installed on an existing container without aneed for tools to cut a hole in the container 220 and so forth. Theelectrical connection 233 could also be similarly fed through a hingearea of the container 220, a door seal between the container 220 and thedoor 221, any small passage or crack in the container 220, or any otheraccess point.

FIG. 2D depicts an example of connecting electrical connection 232between the internal patch antenna 231 and the external patch antenna232. The internal patch antenna 231 can include a connector 251 and theexternal patch antenna 232 can include a connector 252. One end of theelectrical connection 233 cable can include a mating connector 253 andthe other end of the electrical connection 233 can include a matingconnector 254. In this way, the electrical connection 233 can be easilydisconnected from the internal patch antenna 231 and the external patchantenna 232, and a length of the electrical connection 233 can bedetermined based on the appropriate scenario in which the internal patchantenna 231 and the external patch antenna 232 will be placed.

Other shapes and sizes of the electrical connection 233 could be used.In the example shown in FIG. 2D, the electrical connection 233 is in theform of a coaxial cable. A coaxial cable may be beneficial in a scenariowhere a hole exists in a side of the container 220. Alternatively, ahole in the container for the electrical connection 233 could bedrilled. The container could also have a pre-scored hole that an enduser can punch out with a screwdriver or similar tool should the enduser want to feed the electrical connection 233 through such a hole.

FIGS. 3A to 3C depict views of an example of a patch antenna 300 thatcan be used to implement an internal patch antenna such as internalpatch antenna 231 and/or an external patch antenna such as externalpatch antenna 232 depicted in FIGS. 2A-2D. The patch antenna 300includes a ground plane 310 and a patch 320. A spacer 330 can be placedbetween the ground plane 310 and the patch 320. The spacer can be madeout of a dielectric material or an electrically insulative material.Typically, the ground plane 310 is larger in size than the patch 320.The patch 320 can have particular dimensions, such as a width 321 and aheight 322. The ground plane 310 and the patch 320 can be held apart ata distance 323 from each other. Electrical leads 340 can be connected tothe ground plane 310 or the patch 320. In the particular embodimentshown in FIGS. 3A to 3C, one electrical lead 340 a is coupled to theground plane 310 and another electrical lead 340 b is coupled to thepatch 320. While one electrical lead is coupled to each of the groundplane 310 and the patch 320 in the depiction of FIGS. 3A to 3C, morethan one electrical leads could be coupled to one or both of the groundplane 310 and the patch 320.

The shape of the patch 320, the dimensions of the patch 320, and thedistance between the ground plane 310 and the patch 320 can be selectedso that the ground plane 310 and the patch 320 resonate at particularfrequencies. In one embodiment, the height 322 of the patch is selectedto be one half of the wavelength of a target frequency. The ground plane310 and the patch 320 can radiate due to discontinuities at eachtruncated edge of a microstrip transmission line. The ground plane 310can be constructed on a dielectric substrate, using materials andlithography processes similar to those used to make printed circuitboards. When the ground plane 310 is close to the size of the patch 320,it can couple and produce currents along the edges of the ground planewhich also radiate. The current flow is along the direction of the arrow324 shown in FIG. 3B, so the magnetic vector potential and thus theelectric field follow the current. A patch antenna 300 can radiate alinearly polarized wave.

Patch antenna 300 can be fabricated by etching a pattern for the patch320 in metal trace bonded to an insulating dielectric substrate, such asa printed circuit board, with a continuous metal layer bonded to theopposite side of the substrate which forms the ground plane 310. Whilethe shape of the patch 320 shown in FIGS. 3A to 3C is square, othershapes can be used such as rectangular, circular, and elliptical shapes.

In one embodiment, the spacer 330 can be formed of a magnetic material.In this way, the magnetic material of the spacer can sever both thefunction of the spacer for the patch antenna 300 and as a mechanism forremovably mounting the patch antenna 300 to a magnetic surface. Themagnetic material can be flexible, and the materials for the groundplane 310 and the patch 320 can also be flexible. In this manner, theentire patch antenna 300 can be flexible. Such a low-profile, magneticantenna can be removably mounted to a number of magnetic surfaces, suchas a side of a metal cabinet, a curved metallic surface, and so forth.

FIGS. 4A to 4D depict various embodiments of patch antennas 400 that canbe used to implement an internal patch antenna such as internal patchantenna 231 and/or an external patch antenna such as external patchantenna 232 depicted in FIGS. 2A-2D. Each of the patch antennas 400shown in FIGS. 4A to 4D includes a patch 402 that has a different shape.Various shapes of patches can be used for different reasons. Forexample, a particular shape of a patch can tune the patch antenna toreceive and send signals at a particular frequency. In another example,a particular shape of a patch can tune the patch antenna to receive andsend signals at a number of particular frequencies. It is possible thata certain implementation could require antenna shapes or dimensions thatare at odds with the approach of antenna tuning by way of geometriccomponent dimensional adjustment. In such cases, an appropriatecombination of discrete electronic components (e.g., resistors,capacitors, inductors, etc.) can be used to alternatively achievedesired antenna tuning and characteristics.

FIG. 4A depicts a patch antenna 400 a that includes a backplane 401 aand a patch 402 a. The patch 402 a includes slots 403 a. The particularslots 403 a in FIG. 4A include a pair of parallel slots. FIG. 4B depictsa patch antenna 400 b that includes a backplane 401 b and a patch 402 b.The patch 402 b includes slots 403 b. The particular slots 403 b in FIG.4B include two pairs of parallel slots, with one of the pairs ofparallel slots being substantially parallel to the other pair ofparallel slots. FIG. 4C depicts a patch antenna 400 c that includes abackplane 401 c and a patch 402 c. The patch 402 c is formed in twopieces, with a central rectangle and an outer rectangular loop. Thepatch 402 c also includes a slot 403 c that is formed as a rectangularloop in the area between the two pieces of the patch 402 c. In thisscenario, for an electrical lead to be coupled to the patch 402 c, theelectrical lead may be coupled to both of the two pieces of the patch402 c. FIG. 4D depicts a patch antenna 400 d that includes a backplane401 d and a patch 402 d. The patch 402 d is formed in five pieces, witha central plus-shaped piece and four rectangle pieces in the fourquadrants of the plus-shaped piece. The patch 402 d also includes slots403 c that are formed in the areas between the plus-shaped piece and therectangular pieces of the patch 402 d. In this scenario, for anelectrical lead to be coupled to the patch 402 d, the electrical leadmay be coupled to more than one of the pieces of the patch 402 d. Beyondthose shapes depicted in FIG. 4A to 4D, many other possible shapes andsizes of patches are possible.

FIGS. 5A to 5C depict examples of cross sections of patch antennas 500that include protective coverings that can be used to implement aninternal patch antenna such as internal patch antenna 231 and/or anexternal patch antenna such as external patch antenna 232 depicted inFIGS. 2A-2D. FIG. 5A depicts a patch antenna 500 a that includes groundplane 510 a, a patch 520 a, and a spacer 530 a. The patch antenna 500 acan also include a housing 540 a that encases the ground plane 510 a,the patch 520 a, and the spacer 530 a. The housing 540 a, sometimesreferred to as a radome, can be made of any material, such as plastic orceramic, that does not substantially interfere with radio signalspassing from outside the housing 540 a to the ground plane 510 a, thepatch 520 a, and the spacer 530 a. A mechanism or material—such as amagnet, an adhesive material, a hook-and-loop material, and the like—forremovably mounting the patch antenna 500 a to a surface can be placed onthe outside or inside of the housing 540 a. In one embodiment, thematerial for removably mounting can be the spacer 530 a if it is madefrom a magnetic material.

FIG. 5B depicts a patch antenna 500 b that includes ground plane 510 b,a patch 520 b, and a spacer 530 b. The patch antenna 500 b can alsoinclude a protective layer 540 b that covers portions of the groundplane 510 b, the patch 520 b, and the spacer 530 b. The protective layer540 b can be a material, such as a plastic or a resin, that can beapplied on the outside of the ground plane 510 b, the patch 520 b, andthe spacer 530 b in a liquid form and that can harden or cure to formthe protective layer 540 b. The protective layer 540 b can also be amolded material, such as a soft plastic or rubber that is configured tocover the ground plane 510 b, the patch 520 b, and the spacer 530 b. Theprotective layer 540 b can protect the ground plane 510 b, the patch 520b, and the spacer 530 b from damage without substantially interferingwith radio signals passing from outside the protective layer 540 b tothe ground plane 510 b, the patch 520 b, and the spacer 530 b. In oneembodiment, a mechanism or material for removably mounting the patchantenna 500 b to a surface can be placed on the outside of theprotective layer 540 b or the outside of the ground plane 510 b. Inanother embodiment, the spacer 530 b can be made from a magneticmaterial to permit the patch antenna 500 b to be removably mounted to amagnetic surface.

FIG. 5C depicts a patch antenna 500 c that includes ground plane 510 c,a patch 520 c, and a spacer 530 c. The ground plane 510 c is locatedover a substrate 511 c. In this embodiment, the ground plane 510 c canbe a very thin layer, such as a layer of metal foil. The substrate 511 ccan provide structural integrity and protection for the ground plane 510c. The patch antenna 500 c can also include a protective layer 540 cthat covers portions of the ground plane 510 b, the substrate 511 c, thepatch 520 b, and the spacer 530 b. The protective layer 540 c can besimilar to the protective layer 540 b described above. The protectivelayer 540 b can protect the ground plane 510 c, the patch 520 c, and thespacer 530 c from damage without substantially interfering with radiosignals passing from outside the protective layer 540 c to the groundplane 510 c, the patch 520 c, and the spacer 530 c. In one embodiment, amechanism or material for removably mounting the patch antenna 500 c toa surface can be placed on the outside of the protective layer 540 c orthe outside of the ground plane 510 c. In another embodiment, the spacer530 c can be made from a magnetic material to permit the patch antenna500 c to be removably mounted to a magnetic surface.

FIG. 6 depicts a cross-sectional view of an example of a container 620in which a device 610 is stored. The device 610 can be configured tocommunicate wirelessly using one or more of a Wi-Fi communicationdevice, a cellular communication device, an RFID transmitter (eitheractive or passive), and the like. The container 620 may block wirelesssignals or attenuate wireless signals to the point that wirelesscommunication is difficult or impossible. FIG. 6 also depicts aninternal patch antenna 631 and an external patch antenna 632. Theinternal patch antenna 631 and the external patch antenna 632 aredepicted in a form that is similar to the patch antenna 500 b depictedin FIG. 5B; however, the internal patch antenna 631 and the externalpatch antenna 632 can be in the form of the patch antenna 500 a depictedin FIG. 5A, in the form of the patch antenna 500 c depicted in FIG. 5C,or in any other form.

An electrical connection 633 is connected to both the internal patchantenna 631 and the external patch antenna 632. The electricalconnection 633 is fed through a hole in the container 620. As discussedabove, electrical leads of the electrical connection 633 can be coupleddirectly to portions of the internal patch antenna 631 and the externalpatch antenna 632, such as a ground plane or a patch of the internalpatch antenna 631 and the external patch antenna 632. A directedcoupling could be accomplished by soldering the electrical leads of theelectrical connection 633, by welding the electrical leads of theelectrical connection 633, or by any other like method. The electricalconnection 633 can also be coupled to a connector of each of theinternal patch antenna 631 and the external patch antenna 632. Theelectrical connection 633 can pass signals between the internal patchantenna 631 and the external patch antenna 632.

The internal patch antenna 631 and the external patch antenna 632 can betuned to passively transmit and receive wireless signals at the same oneor more target frequencies. For example, the external patch antenna 632can receive a first wireless signal 641. The first wireless signal 641can be at a particular frequency, such as 900 MHz, 1,800 MHz, 2.4 GHz,or any other frequency. The external patch antenna 632 can be tuned toreceive wireless signals at the particular frequency and to send anelectrical signal along the electrical connection 633 to the internalpatch antenna 631. The internal patch antenna 631 can be tuned totransmit wireless signals at the particular frequency, and the internalpatch antenna 631 can transmit a second wireless signal 642 at theparticular frequency. The second wireless signal 642 can be similar tothe first wireless signal 641, though some losses may be incurredbetween the receipt of the first wireless signal 641 by the externalpatch antenna 632 and the transmission of the second wireless signal 642by the internal patch antenna 631. In another example, the internalpatch antenna 631 can receive a third wireless signal 643 from thedevice 610. The third wireless signal 643 can be at a particularfrequency, such as 900 MHz, 1,800 MHz, 2.4 GHz, or any other frequency.The frequency of the third wireless signal can be at the same frequencyof the first wireless signal 641 or at a different frequency. Theinternal patch antenna 631 can be tuned to receive wireless signals atthe particular frequency of the third wireless signal 643 and to send anelectrical signal along the electrical connection 633 to the externalpatch antenna 632. The external patch antenna 632 can be tuned totransmit wireless signals at the particular frequency of the thirdwireless signal 643, and the external patch antenna 632 can transmit afourth wireless signal 644 at the particular frequency of the thirdwireless signal 643. The fourth wireless signal 644 can be similar tothe third wireless signal 643, though some losses may be incurredbetween the receipt of the third wireless signal 643 by the internalpatch antenna 631 and the transmission of the fourth wireless signal 644by the external patch antenna 632.

FIGS. 7A and 7B depict various testing arrangements for testing a patchantenna system. The testing arrangements include a container 710 and awireless signal receiver 711 inside of the container. An internal patchantenna 721 is located inside of the container 710 and an external patchantenna 722 is located outside of the container 710. The internal patchantenna 721 and the external patch antenna 722 are coupled via anelectrical connection 723. The testing arrangements include a networkanalyzer 730. A first electrical connection 731 is connected from afirst port of the network analyzer 730 to the wireless signal receiver711. A second electrical connection 732 is connected from a second portof the network analyzer 730 to a wireless transmitter 740. The wirelesstransmitter 740 is configured to emit a first wireless signal 741. Theexternal patch antenna 722 is configured to receive the first wirelesssignal 741 and to send an electrical signal to the internal patchantenna 721 via the electrical connection 723. The internal patchantenna 721 is configured to transmit a second wireless signal 742inside of the container 710 that can be received by the wireless signalreceiver 711. The network analyzer 730 can control signals transmittedby the wireless transmitter 740 and determine the differences betweenthe first wireless signal 741 transmitted by the wireless transmitter740 and the second wireless signal 742 received by the wireless signalreceiver 711.

The different testing arrangements shown in FIGS. 7A and 7B are similar,except that the external patch antenna 722 is located at differentplaces on the container 710. In FIG. 7A, the external patch antenna 722is located in a horizontal position with respect to the wirelesstransmitter 740. In FIG. 7B, the external patch antenna 722 is locatedin a vertical position with respect to the wireless transmitter 740.

FIGS. 7C to 7E depict possible orientations of the container 710 withrespect a wireless transmitter 740. FIGS. 7C to 7E depict overhead viewsof the container 710, showing a side of the container 710 that includesa door 712. The container 710 can be a metal cabinet and the door 712can have a metal frame with a plastic or glass window. In theorientation shown in FIG. 7C, the door is facing toward the wirelesstransmitter 740 (i.e., at an angle of approximately 0° with respect tothe wireless transmitter 740). In the orientation shown in FIG. 7D, thedoor is facing in a direction substantially parallel to the wirelesstransmitter 740 (i.e., at an angle of approximately 90° with respect tothe wireless transmitter 740). In the orientation shown in FIG. 7E, thedoor is facing away from the wireless transmitter 740 (i.e., at an angleof approximately 180° with respect to the wireless transmitter 740).

Using a variety of orientations depicted in FIGS. 7A to 7E, the effectsof having a patch antenna system and the effects of door position wereinvestigated. In a first test, a series of measurements were recordedwith and without a patch antenna system on the container 710. Thisafforded differential measurements comparing the baseline signalstrength within the container 710 to the affected signal strengthproduced by the patch antenna system (when connected). During thetesting, the orientation of the door 712 of the container 710 withrespect to the wireless transmitter 740 was adjusted. The door 712included a glass portion which can allow wireless signals to pass withmuch less attenuation than the metal portions of the container 710. Inaddition, the orientation of the external patch antenna 722 was adjustedfrom being in a horizontal position on the container 710 to a verticalposition on the container 710. Results from the first test are shownbelow in Table 1.

TABLE 1 Test results with and with patch antenna system Measurement (dB)of wireless signal receiver in container Container No patch VerticalHorizontal configuration antenna system external antenna externalantenna Door at 0° angle −68 dB −71 dB −70 dB Door at 90° angle −82 dB−79 dB −78 dB Door at 180° angle −92 dB −81 dB −84 dB

In a second test, power provided by the network analyzer 730 whensending signals to the wireless transmitter 740 was adjusted. Thispermitted any changes in the experimental data due to propagationvariations to be detected. Additionally, this provided furthersupporting data for the first test. The second test was performed withthe door 712 of the container 710 facing away from the wirelesstransmitter 740 (i.e. at a 180° angle) as that was the lowest baselinesignal strength from the first test. Results from the second test areshown below in Table 2.

TABLE 2 Test results with and with patch antenna system Measurement (dB)of wireless signal receiver in container Container Analyzer- With patchNo patch configuration provided power antenna system antenna system Doorat 180° angle  0 dB −84 dB −87 dB Door at 180° angle  5 dB −82 dB −86 dBDoor at 180° angle 10 dB −83 dB −86 dB

As shown in the results of the first and second tests, there was anincrease in signal strength between measurements with and without thepatch antenna system. The patch antenna system was able to increase thewireless signal field strength inside the container 710 by at least 3 dBin most test configurations and more than 3 dB in some testconfigurations. A 3 dB gain using a patch antenna system effectivelydoubles the strength of wireless signals that are sent into and outsideof the container 710.

Both of the tests described indicate that various orientations of thecontainer 710 and various placements of the external patch antenna 722can affect the strength of the signal inside of the container 710. Whenan internal patch antenna 721 and an external patch antenna 722 areremovably mounted by an end user, the end user may not know where awireless transmitter or receiver is located with respect to thecontainer 710. The end user may also not be able to reposition orreorient the container 710 and the end user may not know the optimallocation of the external patch antenna 722 on the container. In thiscase, the end user may use a trial-and-error method of removablymounting the internal patch antenna 721 and the external patch antenna722 on the container 710. In this case, the ability to easily remove theinternal patch antenna 721 and the external patch antenna 722 andreposition the internal patch antenna 721 and the external patch antenna722 can greatly aid in the end user's ability to try different positionsof the internal patch antenna 721 and the external patch antenna 722until suitable positions are found.

FIG. 8 depicts another type of container that could benefit from the useof a patch antenna system. As discussed above, a container for awirelessly-communicating device can take the form of a cabinet, astorage room, a vehicle trunk, a vehicle compartment, an elevator, asubway compartment, a train compartment, an aircraft compartment, avehicle, and the like. FIG. 8 depicts a vehicle 810, such as anambulance, that can include a wirelessly-communicating device. In oneexample, an AED can be located inside of the vehicle 810 and used totreat a patient that is en route to a hospital. The AED may communicatevia a cellular network with the hospital to provide information aboutthe patient and/or treatment by the AED while en route. In such a case,wireless communications between the AED and the cellular network may bedifficult due to the enclosed nature of the vehicle 810. To address thisissue, a patch antenna system—including an internal patch antenna 820,an external patch antenna 830, and an electrical connection 840 betweenthe internal patch antenna 820 and the external patch antenna 830—toincrease signal strengths of wireless signals passed from outside thevehicle 810 to inside the vehicle 810 and vice versa.

While many of the embodiments described herein include a pair of patchantennas, this is not the only pair of antennas that could be used. Anyother pair of antennas capable of transmitting and receiving theintended frequencies can be suitable, such as dipole antennas. It isalso possible that an internal antenna and an external antenna could bedissimilar antennas. For example, an external antenna could be a dipoleantenna when an internal is a patch antenna.

Conditional language used herein, such as, among others, “can,” “could,”“might,” “may,” “e.g.,” and the like, unless specifically statedotherwise, or otherwise understood within the context as used, isgenerally intended to convey that certain examples include, while otherexamples do not include, certain features, elements, and/or steps. Thus,such conditional language is not generally intended to imply thatfeatures, elements and/or steps are in any way required for one or moreexamples or that one or more examples necessarily include logic fordeciding, with or without author input or prompting, whether thesefeatures, elements and/or steps are included or are to be performed inany particular example. The terms “comprising,” “including,” “having,”and the like are synonymous and are used inclusively, in an open-endedfashion, and do not exclude additional elements, features, acts,operations, and so forth. Also, the term “or” is used in its inclusivesense (and not in its exclusive sense) so that when used, for example,to connect a list of elements, the term “or” means one, some, or all ofthe elements in the list.

In general, the various features and processes described above may beused independently of one another, or may be combined in different ways.All possible combinations and subcombinations are intended to fallwithin the scope of this disclosure. For example, this disclosureincludes other combinations and sub-combinations equivalent to:extracting an individual feature from one embodiment and inserting suchfeature into another embodiment; removing one or more features from anembodiment; or both removing a feature from an embodiment and adding afeature extracted from another embodiment, while providing theadvantages of the features incorporated in such combinations andsub-combinations irrespective of other features in relation to which itis described. In addition, certain method or process blocks may beomitted in some implementations. The methods and processes describedherein are also not limited to any particular sequence, and the blocksor states relating thereto can be performed in other sequences that areappropriate. For example, described blocks or states may be performed inan order other than that specifically disclosed, or multiple blocks orstates may be combined in a single block or state. The example blocks orstates may be performed in serial, in parallel, or in some other manner.Blocks or states may be added to or removed from the disclosed exampleexamples. The example systems and components described herein may beconfigured differently than described. For example, elements may beadded to, removed from, or rearranged compared to the disclosed exampleexamples.

While certain example or illustrative examples have been described,these examples have been presented by way of example only, and are notintended to limit the scope of the inventions disclosed herein. Indeed,the novel methods and systems described herein may be embodied in avariety of other forms. The accompanying claims and their equivalentsare intended to cover such forms or modifications as would fall withinthe scope and spirit of certain of the inventions disclosed herein.

We claim:
 1. A system comprising: a container; a device located withinthe container, the device configured to communicate wireless signals atone or more particular frequencies; an internal antenna removablymounted to an internal surface of the container, the internal antennacomprising a first ground plane, a first dielectric substrate, and afirst patch characterized by a particular shape designed to tune theinternal antenna to receive and radiate signals at the one or moreparticular frequencies; an external antenna removably mounted to anexternal surface of the container, the external antenna comprising asecond ground plane, a second dielectric substrate, and a second patchcharacterized by a particular shape designed to tune the externalantenna to receive and radiate signals at the one or more particularfrequencies; and an electrical connection between the internal antennaand the external antenna; wherein the system is configured such that theinternal antenna is operative to receive a first wireless signal fromthe device and provide a first electrical signal based on the firstwireless signal via the electrical connection to the external antenna,and radiate from the external antenna a second wireless signal based onthe first electrical signal.
 2. The system of claim 1, wherein theinternal antenna is formed as an internal patch antenna and the externalantenna is formed as an external patch antenna, and the system isfurther configured such that the external patch antenna is operative toreceive a third wireless signal, provide a second electrical signalbased on the third wireless signal via the electrical connection to theinternal patch antenna, and radiate from the internal patch antenna afourth wireless signal based on the second electrical signal.
 3. Thesystem of claim 2, wherein the one or more frequencies comprise aplurality of frequencies.
 4. The system of claim 3, wherein the one ormore frequencies comprise at least one of a cellular network frequency,a Wi-Fi frequency, or an RFID tag frequency.
 5. The system of claim 4,wherein the container is constructed of a material that attenuates orblocks wireless signal transmissions.
 6. The system of claim 5, whereinthe container comprises at least one of a vehicle trunk or compartment.7. The system of claim 3, wherein the shapes of the first and secondpatches are selected to tune the internal and external patch antennas toreceive and radiate signals at a plurality of particular frequencies. 8.The system of claim 7, wherein each of the internal and external patchantennas includes a backplane and a patch (402 a) that includes firstand second slots (403 a) formed in the patch so as to be parallel toeach other.
 9. The system of claim 8, wherein the patch of at least oneof the internal and external patch antennas further comprises third andfourth slots formed in the patch to be parallel to each other, whereinthe third and fourth parallel slots are substantially orthogonal to thefirst and second slots.
 10. The system of claim 9, wherein the patch ofat least one of the internal and external patch antennas is formed intwo pieces, including a central rectangle and an outer rectangular loop,and wherein the first, second, third, and fourth slots comprise the areabetween the central rectangle and the outer rectangular loop.
 11. Thesystem of claim 7, wherein at least one of the internal and externalpatch antennas includes a backplane and a patch formed in five pieces,with a central plus-shaped piece and four rectangle pieces in fourquadrants of the plus-shaped piece; wherein slots are formed in areasbetween the plus-shaped piece and the four rectangular pieces.
 12. Thesystem of claim 7, wherein the external patch antenna is tuned to canreceive wireless signals having a target carrier frequency of 900 MHz,1,800 MHz, or 2.4 GHz; and the internal patch antenna is tuned totransmit wireless signals at the target carrier frequency.